Lumbar bone mineral density in prostate cancer patients with bone metastases

Because of the discrepant findings on regional bone mineral density (BMD) in stage IV patients with bone metastases due to prostate cancer, we decided to evaluate BMD of lumbar spines in 30 prostate cancer patients with lumbar spine metastases. These measurements of BMD in lumbar spines were compared with 30 stage IV prostate cancer patients without lumbar spine metastases. Methods. Before BMD measurements, the bone scan with technetium-99m labeled diphosphonate was carried out in all of the men to evaluate lumbar spine metastases. Dual energy x-ray absorptiometry was used to measure BMD in the lumbar spines. Results. There was no difference of age, height, weight, and body mass index between the two group patients. However, significantly higher BMD of the lumbar spines in the 30 patients of prostate cancers with lumbar spine metastases was found (p value <0.05). Conclusions. Our results show that patients of prostate cancers with lumbar spine metastases demonstrated by Tc-99m MDP bone scan have increased BMD in the lumbar spines, possibly because of a predominance of osteoblastic over osteolytic metastases demonstrated by Tc-99m MDP bone scan.